The library houses an incredible collection of some of the world's most impressive books and manuscripts.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

These stained-glass windows are all that remains of a building that was the target of one of the biggest explosions in London after World War II.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The curios of pharmacist and collector Henry Wellcome.

A quiet, semi-secret square with statues of Mahatma Gandhi, Virginia Woolf, and a conscientious objectors stone.

Catacombs turned marketplace.

Stone carvings celebrate the legacy of a now-defunct theatre.

The anatomical-pathological collection of a man who changed surgery.

A jumble of concrete on the corner of one of London’s terraced buildings is actually a work of art.

This pub has roots dating back to 1430 and serves as the setting for multiple Charles Dickens stories.

A naturally mummified 2,000-year-old man.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

Down a pint of ale where the Bishop of Ely's servants slept in 1546.

England's “third-oldest college” has not graduated a single student in over 400 years.

A tongue-in-cheek arcade where the games are based on everyday life.

Down this Cracovian street resides a plaque with a stark message about the city's air pollution.

Inside this Krakow church, an explosion of psychedelic color.